MEMS Sensor Integrating Acceleration and Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MEMS sensors require separate chips for acceleration and pressure sensing, which increases costs and occupies more space, and they struggle with precise detection due to limitations in cavity depth and weight distribution.
Innovation Solution
A MEMS sensor design that integrates both acceleration and pressure sensing on a single chip, featuring a substrate with a first sensor region for acceleration and a second sensor region for pressure, utilizing a first weight portion and beam portion with piezoresistors, and a second weight portion to enhance detection precision, with the first and second membranes forming cavities that allow for deformation-based resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate chips are used for acceleration and pressure sensing, then each sensor can be optimized independently, but the overall device complexity and space occupation increase
Solution Approach 1:
The patent combines acceleration sensing and pressure sensing functions into a single integrated sensor chip. The sensor chip includes a first sensing element for acceleration detection and a second sensing element for pressure detection, both fabricated on the same substrate using compatible manufacturing processes. This integration eliminates the need for separate chips while maintaining the ability to optimize each sensing function independently through dedicated design parameters.
Solution Approach 2:
The sensor chip is designed as a multi-functional device that simultaneously performs both acceleration sensing and pressure sensing operations. The unified chip structure incorporates different sensing elements optimized for their respective functions while sharing common support infrastructure, achieving universal functionality within a single device package.
2Measurement precision
If separate chips are used for acceleration and pressure sensing, then each sensor can be optimized independently, but the cost increases
Solution Approach 1:
The patent combines acceleration sensing and pressure sensing functions into a single integrated sensor chip. The sensor chip includes a first sensing element for acceleration detection and a second sensing element for pressure detection, both fabricated on the same substrate using compatible manufacturing processes. This integration eliminates the need for separate chips while maintaining the ability to optimize each sensing function independently through dedicated design parameters.
3Measurement precision
If cavity depth is increased to improve pressure detection precision, then measurement precision improves, but the device volume increases
Solution Approach 1:
The patent employs a diaphragm structure as a flexible membrane that forms the pressure sensing element. The diaphragm is positioned within the cavity and its deformation under pressure is detected by piezoresistive elements. This thin-film approach allows for effective pressure sensing without requiring large cavity depths, as the diaphragm's flexibility enables sensitive detection with minimal structural volume.
4Measurement precision
If weight distribution is optimized to improve acceleration detection precision, then measurement precision improves, but the manufacturing complexity increases
Solution Approach 1:
The patent optimizes acceleration detection by carefully controlling the mass distribution of the movable structure and the positioning of piezoresistive elements. The design parameters including mass distribution, element positioning, and cavity geometry are optimized to enhance the piezoresistive effect under acceleration while maintaining manufacturability through standard fabrication processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables cost-effective and space-efficient simultaneous detection of acceleration and pressure with improved precision by utilizing a single chip, reducing the need for separate sensors and optimizing cavity depths and weight distribution.
Implementation Method 1
A piezoresistor is formed on the silicon diaphragm that seals the cavity. The movement of the silicon diaphragm accompanied by a change in the pressure in the cavity is used to cause a change in a value of the piezoresistor.
Data Source
AI summary
The present disclosure provides a MEMS sensor. The MEMS sensor includes: a substrate, on which a first sensor region for an acceleration sensor is formed; a first cavity, formed in the first sensor region of the substrate; a first weight portion, including a first membrane formed on the first cavity; a beam portion, supporting the first weight portion; and a piezoresistor, formed in the beam portion. A first opposing surface of the first weight portion facing the first cavity and a second opposing surface of the beam portion facing the first cavity are formed on same plane.